Channels

Snaps are published on channels, which are concurrent versions of the snap, addressing needs such as preview releases and long-term version support.

A channel is composed of three components – a track, a risk, and a branch.

Briefly, a channel is represented in Snapcraft like this:

<track>/<risk>/<branch>

In Snapcraft commands, a typical channel without a branch looks like this:

--channel=latest/edge

Track

The track represents the highest level of organisation for the snap’s release. Typically, it signifies a major release. Authors can use tracks to maintain different major versions of their software.

All snaps have one default track, called latest. Most operations and commands within Snapcraft and the snap ecosystem assume this track, unless otherwise specified. If a snap has need for other tracks, they must be vetted and granted on a snap-by-snap basis by the Snap Store team. The process for requesting a track is outlined in Process for aliases, auto-connections and tracks.

The release semantics for a track is at the snap author’s discretion. A track could, for examples, encompass minor updates, major updates, or long-term support releases. Or, it could signify something else entirely.

Risk

The risk represents the author’s confidence in the release, its readiness, and signals its potential dangers to users. This is the most important component of a channel. With it, authors can maintain multiple variations of the same release of the snap under the same name.

Risk levels are preset by the Snap Store. The available levels are stable, candidate, beta, and edge. Snaps built with the devel grade can’t be released to either the stable or candidate channels.

Snaps are installed to a user’s system with the stable risk level by default.

Branch

The branch represents the smallest meaningful unit of history in the project’s development. It’s an optional component intended to distinguish short-lived or on-demand releases for bug-fixing, one-off testing, and other irregular work.

Branch names convey their purpose, such as fix-for-bug123. Branch names are not, however, discoverable in the Snap Store. Instead, they must be shared by authors to users and referenced by their exact name. If a snap branch has no new publications for 30 days, the Snap Store closes its branch.